We are at a turning point in medicine, Peter Huber explains in his new book, The Cure in the Code. Knowledge of the individual's genetic makeup will soon allow molecular medicine to reach deep inside each of us to cure most of the maladies that afflict us—and perhaps even slow the rate at which we age. First we will learn to understand each person's genome; then we will learn to craft treatments tailored to his or her genetic constitution. But it may not be so easy—and not for purely scientific reasons. Timid regulators at the Food and Drug Administration stand in the way of dramatic medical progress. Reason Science Correspondent Ronald Bailey's review first appeared in the Wall Street Journal.